The Devil You Know
by Kalista77
Summary: Dean falls into the Cage instead of Sam and ends up trapped in Hell with the Devil.
1. Fallen Angel

Dean didn't know what he'd been thinking. One minute, everything had been going to plan. They were all standing there in the cemetery, and Sam had been about to offer himself to Lucifer as a vessel. The rings of the horsemen were in Dean's pocket. All had to do was wait until Lucifer accepted and then open the gate. It was that simple.

But Dean… he couldn't watch the Devil himself possess his little brother. He just couldn't.

So he broke script. He changed the plan. And he was nearly certain that he, and maybe everyone else, was going to die in the process.

The rings were thrown on the ground, and Sam looked at him like he was insane. Dean wasn't even sure how the next few things had happened. He'd thrown himself- physically, bodily- at Lucifer, at the overly powerful archangel, trying to tackle him into the pit. And nothing had happened at first. It had felt like running into a brick wall.

So that was it. He'd taken a risk, and now he was going to die.

Only mere seconds later, not only was Lucifer falling backwards into the gateway created by the pit, but Michael was falling with them. It felt like Lucifer's hands were trying to pry Dean off of him, even while he fell, but Dean wouldn't let go. He couldn't.

And so into the pit they all fell.

At first, it felt so hot. It reminded him of Hell- which was, you know, apt- and Dean couldn't breathe. There was ash and sulfur in his lungs, and he collapsed to the ground, coughing. It was pretty obvious that this place was not meant for humans.

And then a cool- frigid, in fact- hand landed on his back, and he could breathe again.

Forcefully shoving away his memories of Hell, Dean recoiled away from the touch- Lucifer's touch- finding himself on the other side of the rather small cage. Great. He was stuck in a cage the size of a living room with two Archangels. This was definitely going to go well.

Speaking of two Archangels, Dean looked around for Michael, but he didn't see him. And then a punch with the force of a semi-truck came from behind, and Dean stumbled to his knees.

Michael kicked him in the ribs, basically throwing Dean against the wall with the supernatural force of the action.

He didn't look like Adam anymore, Dean noted vaguely as he started coughing up blood. Instead, his human visage had taken on that of a tall, blond, blue-eyed man wearing a navy blue suit. He knelt down and grabbed Dean by the throat, pulling him up and slamming him into the wall of the cage. The metal was hot and started burning through Dean's clothes, sizzling against his skin.

"You fool!" Michael raged, his voice booming and loud in the Cage. "This wasn't how it was meant to be!"

"The fools here are you and I, brother," Lucifer said, shockingly quiet from the other side of the Cage. "Let him go."

Michael snarled again, and Dean could see a glint of insanity in those perfectly blue eyes.

Lucifer, who was also no longer in his old, rotting vessel, glared and suddenly Michael was thrown against the other side of the cage, and Dean was behind Lucifer. He groaned and fell to his knees, his back still feeling like it was on fire.

"Keep your side of the world, brother," Lucifer said coldly. "And I'll keep mine."

Michael hissed, but suddenly curled up in the corner, turning his back to the rest of them.

Lucifer turned to Dean, who recoiled away from him, groaning in pain.

"Dean," Lucifer said quietly, "look at me."

Dean didn't want to listen. He really didn't, but something in him responded to the Devil's tone, and he looked up into dark blue eyes. His new vessel was just generally darker than his old one. His hair was pitch black, his eyes were a deeper, almost navy blue, and even his skin tone was a light brown. As Dean looked into his nearly black eyes, he saw something there he really didn't expect- compassion.

"This Cage wasn't built for humans," the Devil told him softly, and Dean realized that he had an accent- something Middle Eastern, it seemed. "If you don't let me shield you with my grace, it will eat away at your body, and then at your soul, until you become something far less than human."

"A demon?" Dean spat from his position curled up on the floor of the Cage, trying not to cry at the pain ripping through his body, trying to keep his composure.

"No," Lucifer responded evenly, "something even less."

"And I'm supposed to believe that you want to protect me?" The bravado was somewhat ruined by the fact that Dean choked on the last syllable. It felt like there was fire all around him, burning into his skin, burning through his skin, and he had a hard time remembering how Hell could have been worse than this.

Lucifer suddenly rolled his eyes. "You and Michael really were meant for one another," he growled in annoyance, and suddenly his hand was on Dean's forehead, and the pain- well. The pain was just gone.

Dean gasped as it felt like a flood of water and light surrounded his body, but as soon as he could move again, he recoiled back against the cage wall- away from Lucifer.

Lucifer watched him with impassive eyes. "Take that side of the Cage if you wish, but I wouldn't recommend crossing over to Michael's. It seems the last few thousand years of ruling the world on his own has rendered him somewhat insane." He spoke about Michael casually, but there was a hint of pain in his eyes.

And, fuck it, but Lucifer was right. He'd rather deal with the manipulative but surprisingly docile Devil than the enraged Archangel.

For a little while, there was just silence. Dean couldn't stand it. If he were really condemned to an eternity in this place, it seemed that they could at least have a conversation. Right?

"You look… different."

Lucifer laughed. It was a surprisingly sane and pleasant sound. "The cage immediately burnt up our vessels, as it would have yours if I hadn't shielded you."

Dean tried not to look too surprised. He was pretty sure he failed, but Lucifer didn't comment either way.

"These are our forms as we used when we walked among humanity millennium ago. Back before… everything."

Dean arched an eyebrow. "Well, then, you I kind of get- you look Middle Eastern, aside from the eyes, and even those are dark. But how come he looks like freaking Captain America?"

Lucifer rolled his eyes. "Michael was never exactly a fan of blending in. He wanted everyone to know immediately who he was. He succeeded. They used to call him the Golden God."

Dean frowned. "But isn't that… blasphemous?"

Lucifer looked at him for a moment. "There's a lot that you neither know nor understand."

Dean made a face. As true as that might have been, it rankled his pride. "Then explain it," he challenged. "Not like we have anything better to do."

Lucifer's face darkened for a moment. "Perhaps another time."

Dean scoffed but didn't push. On occasion, he did, actually, have self-preservation instincts. "Okay then. What subjects are on the table? Because I get the feeling that talking about how you betrayed your family and created the demon race all because you weren't Dad's favorite anymore isn't going to go over well either." Or maybe he didn't.

Lucifer, to Dean's lasting surprise, just smirked. "It rather depends on whether you wish to yell at me, or actually listen."

"And if I'd just prefer to rail?"

Lucifer paused for a moment and then shrugged. "If it makes you feel better."

Not the reaction he'd been expecting at all. "What happened to the crazy dude who wanted to take over the world? The one who was more than happy to beat me to smithereens?"

Lucifer's entire expression darkened and his body tensed. "Change of heart?" he tried, quiet and almost uncertain.

Dean snorted. "Right."

Lucifer just shrugged.

There was silence again, but it felt more… well, almost companionable this time.

Dean had no concept of the passage of time in the Cage. Michael barely moved; he stayed huddled up in the corner, curled up into a ball, and Lucifer just reclined against the wall across from Dean with his eyes closed. The boredom was excruciating.

"Come on, tell me something!" Dean half-shouted into the silence.

Lucifer cracked his eyes open. "What did you have in mind?"

"I don't know; you're the one who's thousands of years old. You have to have something to say."

Lucifer arched an eyebrow. "You realize I was locked in this Cage alone for the majority of that time, right? Not a whole lot of exciting happenings down here, in case you hadn't noticed," he said dryly.

Dean exhaled heavily, annoyed. "Yeah, but… come on, dude. There's gotta be something."

Lucifer huffed, looking directly at Dean. "What about you? You've spent a decent amount of time in the world- and doing some fairly exciting things from what I've gathered. I'm sure you have a story or two."

And, funnily enough, that was how it started.

One or two stories exchanged between the two of them. Lucifer would tell Dean about before the Fall, about Heaven and the Angels. Dean told Luc about growing up a hunter. He even told him about his mom. They avoided the people who had been left behind by unspoken agreement. Lucifer didn't talk about Castiel. Dean didn't talk about Sam.

Oddly enough, Gabriel had come up once- only once.

Lucifer had been reminiscing on what seemed to be a fond memory of walking among humans before the Fall. Dean wasn't sure how that fit into the Biblical narrative, but he'd learned that Lucifer didn't want to answer questions. It was rare enough that Dean could get him to talk about the past, although he was perfectly willing to banter. And, yeah, bantering with the Devil was shockingly fun.

Regardless, Lucifer had been in one of his rare moods where he was willing to talk about the past. Apparently he'd had a great deal of fun pranking humanity in the youth of their race, and he was telling him a story about how he screwed up this big ceremony that had been held in Michael's honor. Dean had a hard time following sometimes because a lot of the things he was talking about were extremely archaic, but he had gathered that the High Priest was soaking wet and quite a few things were on fire by the end of the night.

"How did Michael react?" Dean asked, chuckling. With the Devil. That was never going to stop being weird.

Lucifer snorted. "Oh, he was pissed as hell, of course. Started ranting on about responsibility and how humans were supposed to respect and fear us and what not." He grinned. "Of course, then Gabriel showed up just covered, and I mean from head to toe, in milk," the grin fled as soon as it had come, and Luc suddenly got very, very quiet. "It derailed the conversation rather quickly," Lucifer muttered.

Dean knew that, according to their unspoken arrangement, he should just let it go. Lucifer never pressed when Dean shut up. He also knew that he was getting way too friendly with the Devil, and the reminder that said Devil had murdered his own brother, who Dean might have kind of admired wasn't helping anything. He kept telling himself that it didn't matter if he was friends with the Devil since he was trapped down here for the rest of eternity anyway… but that didn't excuse being friends with a cold-blooded murderer.

"Yeah, I bet. He was always a funny guy, wasn't he, Gabriel?" Dean commented, his voice cold and harsh.

Lucifer looked up sharply, eyes flashing in a way that told Dean very clearly that he should leave the subject alone.

But maybe Dean had gotten too comfortable around Lucifer, because right now he just felt like scolding him like he might've Sam. "He made a fantastic Trickster. You really should have seen him; I have no doubt you would have approved."

"Dean," Lucifer growled in warning.

"But then, you probably knew all his tricks, didn't you?" Dean finished, harsh, cold, and unrelenting.

In the blink of an eye, Lucifer was across the room, pinning Dean to the cage wall. Yet the protective light that came from Lucifer's grace, the warm feeling that had surrounded him since Lucifer had saved him from Michael, didn't go away. "Stop," Lucifer growled.

"You didn't," Dean spat.

And just like that, Lucifer let him go, and Dean slid down to the floor while the archangel turned his back. "No," he said quietly, "I didn't."

And, yeah, okay, that was unexpected. There was dead silence for a moment.

Dean slowly stood. "Um… Luc? I…. I'm sorry." And yes, he was apologizing to the fucking Devil. "I didn't mean-"

"You're right," Lucifer said abruptly. "I killed him." And Dean was shocked at how utterly cold his voice was. "Anything else you want to rub in my face now?" he snapped, turning. "Because you might as well get it all out now. Or, hell, just wait. You have an eternity."

Dean went very quiet. "I have no idea what was going on with you out there," he said slowly, "but I shouldn't have thrown that in your face. Under any circumstances. I'm sorry."

Lucifer blinked and then slowly cracked a smile. "Get some sleep, Dean."

There was no keeping track of time in the Cage, but Dean still didn't require sleep, so he shrugged and laid down. He froze when he felt a cool presence at his back.

"Don't turn around, Dean," Lucifer muttered, "and stop overthinking. Go to sleep."

And Dean did.


	2. The Resurrection

When Dean woke, it was to low voices in the Cage.

"I don't understand," Michael was saying, "if you have a way out, then why the hell don't you just use it?"

"Because I don't have a way out," Lucifer said with a sigh, sounding like his patience was being strained. "You do. And I will tell you how, if you promise to take Dean with you."

"I don't get it, brother. What is your obsession with this boy?"

"Does it matter?" Lucifer breathed, annoyed. "Will you take him with you?"

"Why are you trying to get rid of me now?" Dean grumbled rolling over in Lucifer's arms. He had no idea how long it had been, but Lucifer curling up next to him while he slept had become rather normal by this point. It was strange how being trapped in a small area with only one person who was willing to talk made such fast friends.

Lucifer exhaled heavily, looking down at Dean. "The Cage is killing you, Dean," Luc murmured quietly. "I can only protect you for so long. You have to get out. Get back to Sam." He paused, exhaling quietly. "Stop the next Apocalypse."

Dean blinked. "So… that douchebag is taking me out of here?"

"Yes."

"And you're stuck here. By yourself. Again."

Lucifer smiled faintly. "I'm the Devil, Dean, remember? This is what I deserve."

"You're different. Different than you were up there. I don't know why, but-"

"Dean," Lucifer whispered, shaking his head slightly, "stop. I'm the bad guy. I'm the Devil, you're a hunter, and you have to stop. You're going back to Sam. You're going to go find your brother, pick up where you left off, and forget about all of this."

Dean exhaled heavily. "But if Michael can get out, why can't you?"

Lucifer chuckled. "You want me to get out, Dean? You do remember how that went last time, don't you?"

Dean rolled his eyes, sitting up. "Dude, you're not-"

"Yes, I am," Lucifer snapped, cold and ruthless. "Now get the hell out of here."

"As touching as this is," Michael drawled, "how exactly are we managing that?'

"Flight," Lucifer said simply. "With a combination of both of our Graces pushing at a single point on the Cage, and the power of your wings, you should be able to make it through. With Dean."

"That's going to be a close call," Michael commented.

Lucifer smiled sharply. "Well, you better hope that it works, because that's all I've got."

"It'll be a close call even without the extra baggage."

Lucifer narrowed his eyes. "If you even think about leaving him here, I won't help you with my Grace, and you'll be trapped half inside the Cage and half without- flickering between dimensions for the rest of eternity."

Michael smirked. "Fine then. The little human gets to come with me. Although it's not like he'll have a body once you get him back upstairs."

Dean blinked, surprised, but Lucifer seemed unconcerned. "I'll worry about that. You just get him out of here."

"One question," Michael said after a moment, "if you know there's a weak point, why'd you never exploit it?"

Lucifer shrugged. "You need the power of two Archangels to even have a prayer. It's not as though I've ever had a spare one of those on hand."

Michael regarded him for a moment, and then smiled like he knew something that the others didn't. "So, when do we leave?"

"As soon as possible," Lucifer answered, all business, "before the Cage wears down your power too much."

And before Dean could say another word, asking for- honestly, he didn't even know, time, an answer to all the questions Lucifer had always avoided, the chance to ask why the hell the Devil even cared about him- Michael grabbed him by his upper arm and the entire world seemed to shift around him.

There was a blinding light that Dean could feel even behind his closed eyelids, and an intense pressure all over his body. It built and it built until he couldn't do anything but scream, yet there was no air in his lungs. For a few startlingly frightening moments, Dean couldn't breathe, he couldn't move, and he couldn't even scream. He felt panic start to claw away at him from the inside out, fear creeping through his bones, and then-

Dean snapped awake.

He sat bolt upright, hands roaming over his own body, checking it for injuries or anything else. He seemed… well, he seemed fine. When he'd been rescued from Hell, he'd woken up in a coffin, but now he was just lying on an ordinary green field, his body was fine, and he didn't even feel like he'd been missing for… however long it had been.

Slowly, he got to his feet, testing his legs, his muscles, but they weren't even cramped. Whoever had fixed his body, they had done a damn good job of it.

He checked his pockets and frowned as he came upon a folded piece of paper, pulling it out to read the note written in elegant, left-handed writing.

I hope your body is put back together properly. I suppose if you turn up with a tumor in a month or so, you'll know who you have to blame.

I found Sam. His address is at the bottom of the paper.

Have a good life, Dean.

The note wasn't signed, but Dean knew exactly who had written it. So the Devil was left-handed. That was good to know, he supposed. Dean smirked, but he couldn't help but feel just a bit guilty. Of course, that was ridiculous. He and Sam had gone through so much shit because of Lucifer, and they had been willing to sacrifice everything to put him away. Now Dean was feeling fucking guilty because he didn't escape? Yeah, that made sense.

"Get your head in the game, Winchester," Dean muttered to himself before promptly heading off to the road that he could hear in the distance. He had no idea where he was, but Sam, as it turned out, was in Arizona. So he was going to go find him. Simple.

The Devil was in the Cage, where he belonged.

And Lucifer… well. Dean would get used to sleeping without his presence easily enough. And if he didn't, he had gone without sleep plenty of times in the past. It's not like he missed him or anything.

He sure as fucking hell was not feeling goddamn sympathy for the Devil.


	3. Son of Man

Dean swore silently to himself that the next person who asked him if he was okay was going to get their head slammed through the nearest wall.

He was fine.

Yes, sure, he'd spent the last three months in a Cage with the Devil and a crazy Archangel who wanted to wear his skin, but, hey, at least time in the Cage seemed to move at the same rate as time in the real world. It had really only been three months. What Sam and Bobby seemed to be having a hard time with was the fact that Dean claimed they didn't hurt him. Not that he went -into details about his time in the Cage, but they seemed to think that he was lying through his teeth.

And maybe they had a right to be suspicious. After all, when he'd come back from Hell, it wasn't like he'd been entirely upfront with them about that. But still. Aside from that first incident with Michael, neither of them had laid a hand on him. To hurt him, that is. Although it wasn't like Lucifer had touched him all that casually either. Just slept next to him. Which, yeah, weird, but Dean was doing his damned best not to think about that, because every time he thought about Lucifer he got this empty pit in his stomach and the cold space at his back when he slept just got more pronounced.

Okay, maybe he wasn't fine, but Sam and Bobby didn't need to hear about how he apparently missed the goddamn devil.

He was totally fucked.

But time went on, slowly, inexorably, until they had to confront an enemy that they couldn't face alone.

His name was Dick Roman, or, at least, his vessel's name was, and apparently he was one of the nastiest creatures ever to walk on God's green earth. Instead of preventing a civil war in heaven, as Castiel had hoped, it seemed that Michael's return had only inflamed it, and Cas… well… he'd made some damn bad decisions. Now the Leviathan were loose, and Cas was possibly dead, and thanks to Michael being a celestial douche-bag, they had no way to stop them.

According to Michael, only an archangel had the power to kill the King, and, well, neither he nor his lackey Raphael seemed interested in lifting a finger to help them. Except the thing was… there was another Archangel.

"Dean, are you insane?" Sammy demanded, angry and shocked, and, well, maybe he had a right to be.

"Do you see any other options?" Dean snapped back, not in the mood to defend his admittedly dumb suggestion.

"Besides asking Crowley for a ride into Hell to visit with the Devil? Because one insane, supernatural being trying to destroy the world at one time isn't enough?"

"Michael won't help us, and if anybody knows another way to get rid of them, it's someone who helped get rid of them in the first place."

"You think Lucifer will help us?"

"Listen, Sam, believe it or not, he was the less douchey one while we were in the Cage, so, yeah, I think maybe we should give it a shot."

Sam froze, looking at Dean for a long moment. "You don't ever talk about it," he said quietly.

Dean rolled his eyes. "And I'm not planning to start. No chick-flick moments, Sam, you know that. Let's just go summon Crowley."

"You should cut Crowley some slack," Lucifer had commented with a smirk. "Ruling Hell isn't exactly a walk in the park."

Dean just looked at him. "Are you seriously defending a demon right now?"

Lucifer shrugged. "Come on, Winchester. Even you have to admit that Crowley is better than most. You should quit stabbing him in the back."

Dean shook himself from the memories and ignored Sam's grumbling. However, if he was slightly more willing to hold up his deal with the demon this time around, it wasn't like anyone else had to know. Anyway, Crowley didn't want the world destroyed any more than they did, so it was surprisingly easy to get him to cooperate.

Right up until they told him what they wanted.

"You want to want?!"

"Just talk to him," Dean tried to pacify.

"That's not how it works, Squirrel," Crowley drawled. "The Cage is impenetrable."

Dean bit back the automatic, "obviously not," that wanted to spring to his lips. "Then just… put me in there with him. Can you do that? Temporarily?"

"Dean!" Sam exclaimed, stunned.

Crowley narrowed his eyes. "There might be a way using astral projection. You wouldn't physically be down there, but then again, you never really were. Your body that fell into the Cage was destroyed. Somebody built you a new one." He sniffed. "With a touch of Grace."

Dean shifted uncomfortably. "If there's a way to do it, then let's do it. What are we waiting for?"

"Dean, this is insane!"

"Do you have any other options, Sammy?"

"Dean, you are jumping into this way too quickly. Maybe we should just-"

But analyzing their options was the last thing Dean wanted to do. He turned back to Crowley, cutting Sam off. "Right then; let's do this."

Falling into the Cage didn't really feel like last time. This time, it felt more like he was floating, gently, down into the darkness. When his feet hit the floor of the metal, he looked around, glancing at his own solid-looking arms and examining his surroundings.

"What the hell are you doing here?"

Dean looked up, finding Lucifer staring at him looking somewhat irritated. "We need your help."

The Devil pursed his lips and then breathed a chuckle. "Seriously? You do remember that I'm-"

"Yeah, yeah, the Devil I know," Dean cut him off, annoyed. "But I don't think that you want the world destroyed any more than we do right now, regardless of what you were doing when you were up there before, and it's in danger, so would you tell me how to kill the Leviathan?"

Lucifer just stared at him for a beat before letting loose a string of curse words in dead languages. "Who the hell let the Leviathan out?"

"Cas," Dean admitted. "He was trying to get enough power to rival Michael and Raphael and bring peace to Heaven or some such shit." Dean hesitated. "He killed Raphael."

Lucifer snorted. "Well that was bound to happen at some point. I'm surprised Michael didn't do it himself."

Dean frowned. "What?"

Lucifer just shook his head. "It's not important. When you get back upstairs, smack Cas upside the head for me, would you?"

Dean found himself grinning crookedly and- what the hell was wrong with him? "Cas… he's-"

"Not dead," Lucifer drawled, sounding positive. "Trust me. Cas is fine. Or he will be, anyway." He shook his head fondly. "He was always his favorite."

"I have no idea what you're talking about," Dead stated flatly.

"I know." Lucifer flashed a grin that quickly faded. "You can't kill the Leviathan. You're going to have to banish them, and I can tell you how. I'll give you the ritual; everything that you're going to need to put them back in Purgatory."

"Thank you," Dean breathed. He knew this was a good idea.

"But you have to do something for me."

Oh shit.

"Lucifer-"

"I'm not asking for my freedom, Dean," he sounded bemused. "I just want you to deliver a message to Michael for me. That's all." He handed Dean a letter written in Enochian, which, where he got the paper was a mystery to Dean.

"I'm not actually here, how-"

Lucifer gave him a look. "I rebuilt your body and left a note in your pocket last time you left. You really think that I can't put a letter on you when you get back?"

"Fair enough."

"So we have a deal?"

"What does the letter say?"

Lucifer huffed a sigh. "Dean. Do we have a deal?"

Dean looked at him for a long moment. "Yeah. We do."

Lucifer grinned. "Okay then."

When Dean got back to his own body, the letter was in the pocket of his jeans. He didn't mention it to Sam or Crowley, but he did make a point to thank Crowley, which he was fairly certain surprised all three of them.

Michael got the letter. He didn't seem happy about it.

The Leviathan were banished. Dean went with them.

Purgatory was all blood, primal instincts and urges, death and hunting. Sometimes, when Dean felt himself falling a little too far into the depths of it, he thought he heard a familiar voice. The rest of the time, he thought he was going crazy.

He didn't remember to smack Cas over the head until he found him in Purgatory. When he told the younger angel it was from Lucifer, Castiel got very quiet for a while.

Cas came with him from Purgatory. There were moments when he thought that maybe, just maybe, the angel was planning on staying behind, but, in the end, he stuck with Dean. Dean was grateful for that.

Saving people, hunting things, the family business. Life was back to normal. The letter still bothered him, but nothing disastrous had happened. Maybe Lucifer was just telling Michael off or something.

Dean was standing in the middle of a random cemetery in the dark having just finished a standard salt and burn. Sammy was with the damsel in distress, but he was fine now. The ghost was gone.

"Hey, Deano."

Dean froze at the sound of an all too familiar voice that he honestly thought he would never hear again. He turned around slowly, literally unable to comprehend the sight before him, much less comment on it.

The Trickster, the Archangel, the dead Archangel, smirked broadly, wiggling his eyebrows. "Time to repay our debts, kiddo. What do you say that the two of us go and rescue the Devil?"


End file.
